//Complete the GetLines at the end of the file

using System;

using  System.Text;

using System.Collections.Generic;

using System.Environment;

public class Program

{

    public static void Main()

    {

        var input = new []{

            /* 1*/("", Array.Empty<string>()),

            /* 2*/("Single line", new []{"Single line"}),

            /* 3*/("Line 1\nLine 2", new []{"Line 1", "Line 2"}),

            /* 4*/("Line 1\rLine 2", new []{"Line 1", "Line 2"}),

            /* 5*/("Line 1\r\nLine 2", new []{"Line 1", "Line 2"}),

            /* 6*/("Line 1<NEL>Line 2", new []{"Line 1", "Line 2"}),

            /* 7*/("No break\\<NEL>between these", new []{"No break<NEL>between these"}),

            /* 8*/("No break\\\rbetween these", new []{"No break\rbetween these"}),

            /* 9*/("No break\\\nbetween these", new []{"No break\nbetween these"}),

            /*10*/("No break\\\r\nbetween these", new []{"No break\r\nbetween these"}),

            /*11*/("Line 1\rLine 2\nLine 3\r\nLine 4\\<NEL>continues<NEL>a\\\r\\\n\\\r\nends", new []{"Line 1", "Line 2", "Line 3", "Line 4<NEL>continues", "a\r\n\r\nends"}),

            /*12*/("Line 1<NEL\rLine2", new []{"Line 1<NEL", "Line2"}),

            /*13*/("Line 1<NEL\rLine2\\", new []{"Line 1<NEL", "Line2\\"}),

            /*14*/("Line 1<NE", new []{"Line 1<NE"}),

            /*15*/("\r\n\n\r", new []{"", "", "", ""}),

            /*16*/("Line\r", new []{"Line", ""}),

            /*17*/("Line\n", new []{"Line", ""}),

            /*18*/("Line\r\n", new []{"Line", ""}),

            /*19*/("Line\n\r", new []{"Line", "", ""}),

            /*20*/("Line\fLine", new []{"Line\fLine"})

        };

        int i = 0;

        int fail = 0;

        foreach(var testCase in input)

        {

            i++;

            var expected = testCase.Item2;

            var actual = GetLines(testCase.Item1);

            Console.WriteLine($"{i} " + testCase.Item1.Replace("\r", @"\r").Replace("\n", @"\n"));

            if(expected.Length != actual.Length)

            {

                Console.WriteLine($"\t✖ Array lenghts differ: Expected {expected.Length}, actual {actual.Length}");

                Console.WriteLine("\t\tExpected:");

                foreach(string l in expected) Console.WriteLine("\t\t\t" + l.Replace("\r", @"\r").Replace("\n", @"\n"));

                Console.WriteLine("\t\tActual");

                foreach(string l in actual) Console.WriteLine("\t\t\t" + l.Replace("\r", @"\r").Replace("\n", @"\n"));

                fail++;

            }

            else

            {

                bool ok = true;

                for(int j = 0; j < expected.Length; j++){

                    if(expected[j] != actual[j])

                    {

                        ok = false;

                        Console.WriteLine($"\t✖ Line {j + 1} differs: Expected: {expected[j].Replace("\r", @"\r").Replace("\n", @"\n")}, Actual: {actual[j].Replace("\r", @"\r").Replace("\n", @"\n")}");

                    }

                }

                if(!ok) fail++;

                else Console.WriteLine("\t✔");

            }

        }

        Console.WriteLine();

        if(fail == 0)

            Console.WriteLine("✔ All tests passed");

        else

            Console.WriteLine($"✖ {fail} tests failed");

    }

    /// <summary>Splits text by lines</summary>

    /// <remarks>

    /// Expected line separators are: \r, \n, sequence \r\n, sequence <NEL>

    /// Line separator is ignored if preceded by \. In this case the separator will be part of the line on output (i.e. "line" will span multiple lines - contain new line character)

    /// If \ is before any other character, the character goes to output without \.

    /// If \ is at the end of the string it just goes to output as \.

    /// Keep empty lines.

    /// </remarks>

    public static string[] GetLines(string text)

    {

       string[] returnValue;

            returnValue = new string[] { };

            string text = "asdasd/nsdaasd";

            if (text.Split(Environment.NewLine).Length > 0)

            {

                returnValue = new string[] { new text.Split(Environment.NewLine).ToArray() };

            }

        }

    }

}

​